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Investigations of Room Acoustics with a Spherical Microphone Array

Most room acoustic parameters are calculated with data from omni-directional or figure-of-eight microphones. Using a spherical microphone array to record room impulse responses can open up several new areas of inquiry. It can yield much more information about the spatial characteristics of the sound field, including the diffuseness of the sound field and the directions of individual reflections. A 16-channel microphone array was designed, built, and tested with both simulations and simple, controlled sound events. Room impulse responses were then measured in reverberant rooms used for music from stage and audience positions, and the results were analyzed using beamforming techniques to determine spatial information about the sound field.